Amplifier current variations and amplifier gain variations observed in pseudomorphic high electron mobility transistor (PHEMT) technology in both enhancement mode and depletion mode operation are unsatisfactorily large for high yield production. Attempts to solve this issue have focused on threshold voltage control through enhanced epitaxial processes and process variation limits. However, such processes and techniques have not yielded any widely accepted improvements. Others have proposed transistor bias techniques at the cost of increased supply voltage sensitivities, while yet others have focused on amplifier circuit topologies that are not suitable for low-noise amplifier operation. What is needed is bias circuitry that compensates for amplifier current variations and amplifier gain variations during either or both enhancement mode and depletion mode operation.